1. Technical Field of the Invention
The present invention relates generally to a mash/lauter tun and method of use thereof, and more specifically to a mash/lauter tun comprising a container with a double false bottom filter comprised of two perforated plates disposed parallel with a space therebetween for receiving filtration media. The container further comprises thermometers extending to near the center of the tun and a rotating heat exchanger with sparge nozzles.
2. Description of Related Art
Brewing is a complicated and delicate process, which is described in detail below. It is the production of alcoholic beverages and alcohol fuel through fermentation, whereby sugars get converted into alcohol. The exact process of brewing has generally remained stable over time; however, the equipment for conducting the process has seen changes, particularly for the home brewing community. The process of brewing beverages from grain, notably beer, begins with two primary raw materials: malted barley and liquid water. Other grains, such as, for exemplary purposes only, wheat, may also be utilized. Wort for brewing the beer is obtained from mashing the barley, and is later brewed with hops to obtain the desired taste. Lastly, yeast is added to ferment the sugars into alcohol.
Generally, home brewers invest a great deal time and energy into the process of brewing their own beer. First, the malted barley is added to form a slurry in a bath of warm water, which needs to be held at a constant temperature (typically between 148-158 degrees Fahrenheit). The mixed content of malted barley and water is referred to as mash and undergoes a process known as mashing. During the mashing process, enzymes cause chemical reactions to break down the complex starches in the barley into simpler sugars, thus making “wort”. Wort refers to the liquid extracted from the mashing process and contains the sugars that will later be fermented to produce alcohol. This production of wort takes places in a vessel known to those skilled in the art as a mash tun.
Secondly, separation of the wort from the mash, often regarded as the most difficult step in the brewing process, comes next, and is initiated when the temperature of the mash is raised to around 170 degrees Fahrenheit. In previous brewing systems, this separation stage usually takes place in a separate vessel, known to those in the art as a lauter tun. Lauter tuns contain the necessary components needed for the separation process; more specifically, they contain a sparger and a false-bottom filter. The sparger sprinkles hot water over the grain bed to rinse any remaining sugars from the grains, while the filter allows the sugar water (wort) to drain out of the vessel, while still holding the granular remains inside the vessel.
Two common systems have arisen in home brewing to streamline the brewing process described above: Recirculating Infusion Mash System (RIMS) and Heat Exchanged Recirculating Mash System (HERMS). Both of these systems continuously re-circulate the wort either through an electric heating element (RIMS), or through coils located in a separate hot liquid tun (HERMS). Recirculation of the wort through the mash allows the mash to either maintain its current temperature, thus continuing the mashing process, or the temperature of the mash can be raised to halt the mashing process and start the separation stage. However, the above systems come with potential drawbacks. First, the time it takes to raise the mash to the temperature required to transition from the mashing process to the separation process is considerable for both systems. To decrease this time, the wort would have to be heated to potentially dangerous or damaging temperatures, as even the slightest excessive rise in temperature will essentially scorch and thus ruin the wort.
Secondly, the systems require that the wort constantly be recirculated, which has several disadvantages in and of itself. Separation of the wort from the mash is often regarded as a highly difficult step due to the delicate nature of the wort and mash, and, as such, adding the wart back to the mash and causing repeated separations can eventually build to several large problems. If the wart is drained too fast, the mash bed may lack buoyancy and will instead compact against the false-bottom drain, essentially sealing it off. Also, continuous recirculation of the wart through the mash can lead to uneven heating in the form of stratified heat layers, thereby decreasing the wart quality. Accordingly, an apparatus that decreases the time to change the mash temperature and separate the mash is beneficial.
Other devices have sought to counter some of the inherent flaws of current home-brewing equipment, particularly the problem of combining operations into a single mash/lauter tun. Present devices teach methods of separation of the wart from the mash, whereby the mash goes through several filtrations with the goal of obtaining the most pure wort possible. The mash makes its way through progressively more selective filters, such that for each filter passed, more grain will be filtered out and more pure wort will be allowed to drain through. However, for these filtrations to work, the entire process must be spaced apart over subsequent steps instead of one continuous step to minimize the chances of clogging one of the filters. Such clogged filters must be periodically backflushed to clear the filter surface. Accordingly, an apparatus that eliminates the step of having to reverse the flow of filtrate through the filters to flush the system of any inevitable build-up is advantageous.
Furthermore, most systems lack the ability to be readily cleaned of residual wort upon the completion of processing. Thus, sanitation issues can arise if such devices are not thoroughly cleaned.
Another mash/lauter tun teaches a heating system that does not entirely depend on the recirculation of wort through the mash to either maintain or raise the mash temperature. Instead the heating process is aided by a separate hot water tank that partially surrounds the mash tun. By raising the temperature of the water inside the hot water tank, the mash is heated by conduction. However, this system potentially suffers from severe uneven heating conditions of the mash, because the mash to the outside of the mash/lauter tun will be heated more rapidly to a higher temperature than the mash in the center of the tun, thus leading ultimately to decreased wort quality. Also, control of the mash temperature remains through indirect means, making specific, and sometimes very minor, temperature adjustments a difficult and long task. As such, a mash/lauter tun apparatus that provides for even heating conditions is advantageous.
Lastly, there are mash/lauter tuns that utilize known rotating heat exchangers inside the tun vessels. Hot liquid or steam is passed though rotating tubes, thereby heating the mash that surrounds them. As these tubes are in constant rotation within the vessel, they actively mix the mash as they heat it, thus more evenly distributing heat amongst different parts of the mash. The devices with a rotating heat exchanger inside the mash/lauter tun follow a generic pattern for the heating tubes, typically either two coil arms festooned from top to bottom (one hundred eighty degrees separation) or four arms (ninety degree separation). That is, the tubes are not positioned in such a manner as to lead to maximum heating efficiency of the mash and preclude utilization of thermostats or other measuring instruments from being effectively utilized, since such instruments would be impacted by rotation of the tubes if they extend to the center of the mash. However, the downfall of such previous devices is that the tubes of the heat exchanger do not extend through a large portion of the mash. As such, it would be beneficial for an apparatus that provides a larger surface area of contact with the mash and that leaves space for measuring instruments to extend to near the center of the mash.
Stirring of the mash by the rotating heat exchanger also leads to grinding of the mash grains against bottom filters, particularly when utilizing the stainless steel filters of many devices, wherein the grinding reduces the size of the grains such that same pass through the filter and remain with recovered wort, thereby contaminating same. Accordingly, softer filter materials are desirable to minimize grinding of the mash grains.
Therefore, it is readily apparent that there is a need for a mashing and lautering apparatus that efficiently heats the mash without overheating and which accommodates measuring instruments that extend through the mash, and which further permits easy separation of the wort from the mash without clogging the filter bed.